Vertex Pharmaceuticals has reported the interim data from two treatment arms of the Phase 2 Zenith study, investigating an interferon-free (all-oral) treatment regimen of the non-nucleoside polymerase inhibitor VX-222 plus Incivek (telaprevir) tablets and ribavirin in people with genotype 1a or 1b hepatitis C.
Approved by the US Food and Drug Administration (FDA) and Health Canada, Incivek is an oral medicine that acts directly on the hepatitis C virus protease, an enzyme essential for viral replication. VX-222 is a non-nucleoside inhibitor of the HCV NS5B polymerase.
The Phase 2 study enrolled 152 people to examine the safety, tolerability, on-treatment antiviral activity and the proportion of people in each treatment arm who achieve a sustained viral response.
In the study, 11 patients met the criteria of having undetectable hepatitis C virus at weeks two and eight of treatment, of which nine patients achieved SVR4 (undetectable hepatitis C virus four weeks after the end of all treatment).
The company said data from the ongoing Zenith trial will be submitted at a medical meeting in the first half of this year.
Vertex Pharmaceuticals chief scientific officer Peter Mueller said the goal of the study is to develop well-tolerated, interferon-free treatment regimens with high viral cure rates and short treatment durations for people with hepatitis C.
"We believe we're well-positioned to achieve this goal by exploring various combinations within our portfolio that includes Incivek, VX-222 and two structurally-distinct nucleotide polymerase inhibitors," Mueller added.
Based on the Zenith data, and pending discussions with regulatory agencies, the company intends to pursue a Phase 2b study evaluating multiple interferon-free combination regimens of Incivek, VX-222 and ribavirin with total treatment durations as short as 12 weeks.
The study data will also be used to design a Phase 3 programme with the aim of submitting a New Drug Application (NDA) to the FDA for the company's first interferon-free regimen for genotype 1 (1a and 1b) patients by the end of 2014 or beginning of 2015.
The company has begun the first 7-day viral kinetic studies of ALS-2200 and ALS-2158 in people with genotype 1 hepatitis C, safety and viral kinetic data from the studies are anticipated in the second quarter of 2012.